php - Not able to perform a PDO Prepare Statement -

'm trying execute following code:

try  {     $conn = new pdo('odbc:clasges5');                $conn->setattribute(pdo::attr_errmode, pdo::errmode_exception);     $sql = "insert codpais (clapai,codpas,nompas) values (:clapai,:codpas,:nompas)";     $q = $conn->prepare($sql);     $clapai = 31;     $codpas = 'test codpas';     $nompas = 'test nompas';     $q->bindparam(':clapai', $clapai, pdo::param_int);     $q->bindparam(':codpas', $codpas, pdo::param_str);     $q->bindparam(':nompas', $nompas, pdo::param_str);     $q->execute();         } catch(exception $e) { echo $e->getmessage(); } 

the database (visualfox dbase via odbc) looks this: - table codpais - clapai primary key - codpas string - nompas string

i'm getting error invalid character value cast specification: 302

the problem "clapai". if perform update codpas or nompas works ok, if try tu update clapai value throws same error.

any tips fix that? btw. it's better use named placeholders or question marks? advantage?